The highs and lows of Farming French Beans

March
15,2019,Nairobi. Recently, French beans farming has become common in
most parts of the country with the European Union is a major outlet of French
beans. In Kenya, the green beans farming is a two-way business where you can
sell the product as expected and generate a lot of profit or get a large
portion of the product rejected and count losses.
French beans perform well in wet and warm parts of the country such as Muranga,
Thika, Nakuru, some parts of Kajiado, Machakos, Kisumu, Western Kenya, and in
Mt Kenya Region, where there are adequate water supply and well-drained soils.
Weather patterns facilitate the market seasonality on both the Kenya market and
the European Union Market. There are seasons when
the demand for green beans is high while there are others where it is low.

High Season

The high season runs from October to April. Since the
European Union Market is faced by winter during this period, they are forced to
import the beans. During this period, the French beans supplied are mainly from
irrigation which makes the supply to be relatively low. In the process, the
prices rise. At the same time, the quantity of French beans rejected is
relatively low. Farmers who harvest between October and April get a lot of
profit from the from the green beans.

Low Season

Each year, the low season runs from early June to late September. During this time, the weather conditions in the European Union are favorable for French beans and therefore they can produce their own resulting in low demand. At the same time, the supply of the beans is quite high from many farmers who rely on the long rains which result in flooding of French beans in the market. Exporters of green beans thoroughly inspect the beans and only export what is of high quality. The low demand and high supply lead to a significant drop in market prices and an increase in the rejection rate. Farmers who grow green beans during this period get most of their products rejected and sometimes even lack a market for their produce, making them to only count losses. Green beans which are intended for export must meet the following requirements: They should be clean, of fresh appearance, intact and free from excess moisture. Rejection of export horticultural produce can be facilitated by the presence of pests, low quality, high residue deposits and inability to meet the standards set by bodies such as KEPHIS.

Major pests and diseases

Pests
and diseases can lead to the rejection of the entire supplied produce.
Furthermore, it can lead to the termination of the contract between the farmer
and the export company. Pests that affect French beans include:

Bean fly

The larva of this pest tunnels causes damage to the plants’ vascular tissue leading to petiole droop and plant vigor. Bean fly is common on beans from emergence up to when the plant is 4 weeks old. However, it can still be seen on older crops.

Thrips

The nymphs and adults feed on the flower structures and the
leaves resulting in leaf fall and flower buds abortion.
Aphids

They cluster themselves on the leaves, and stem of the
beans and suck the plant sap. Aphids lead to malformation and stunted growth on
the infested parts. When the leaves fold, the photosynthetic area reduces.

Red spider mites

These pests result in the formation of webs and yellow stipples on the underside of the French beans’ leaves.

Whiteflies

They suck the plant sap leading to curling of leaves, and
in severe cases result to leaf drop.

Cutworms

These caterpillars are quite common in young plants, where
they cut the stem either above or below the soil level.

Diseases

Rust

It facilitates the formation of brown reddish spots on pods, stems, and leaves.

Anthracnose

This is one of the most dangerous diseases affecting French beans. Anthracnose results in the formation of brown lesions on stems and pods and black spots on leaves. In the presence of water, it spreads rapidly interfering with the rate of photosynthesis.

Downy mildew (Blight)

Blight causes the development of a grey or whitish mass of
fungal growth on the leaves. This reduces the photosynthetic area of the plant.

Fusarium wilt

Wilting results in yellowing of leaves on the infected
plants. With time, the vascular tissues are discolored and eventually, the
plant dies.

Angular Leaf Spots

The disease results in the formation of angular brownish
spots on stalks, leaves, and pods. In severe cases, it can lead to premature
leaf fall.

Powdery mildewIt results in chlorosis and in severe cases it makes the leaves to drop off.

Bean Common Mosaic

This disease is commonly spread by aphids, and leads
to stunted growth, leaf rolling and curling, and the formation of mosaics on
the leaves.

Pesticide residue deposits

The high application of pesticides on French beans has
facilitated to increase inspection by the importers. Detection of pesticide
residue on the green beans has greatly affected the export market. Farmers have
therefore been urged to adopt Integrated Pest Management to ensure that the green
beans don’t exceed the Maximum Residue Limit. French beans farming is one of
the most profitable ventures in Kenya if done on the high season. They are easy
to grow and can be grown on a small piece of land.